1. Field of the Invention
This invention relates to a system for generating electrical energy from fluid currents, especially currents in water.
2. Description of the Related Art
There are a variety of patents on different devices for generating electricity from ocean currents. These include the following: U.S. Pat. Nos. 4,313,059; 4,335,319; 4,383,182; 4,500,259; 4,850,190; 6,006,518; 6,109,863; 6,734,576; 6,781,253; 6,849,963; 6,856,036; 6,955,049; and 6,998,730.
Although intended to convert wind energy, the device of U.S. Pat. No. 4,756,666 employs sails attached to an “aerial cable railway.” Similarly, U.S. Pat. No. 6,498,402 discloses parachutes connected to a continuous cable for converting wind energy to electrical energy. And U.S. Pat. No. 3,992,125 utilizes blades moving within a housing underwater in order to generate electrical power.
Furthermore, there are at least nine other patents and five patent applications dealing with the production of electricity from water currents. The patents are U.S. Pat. Nos. 3,912,937; 4,224,527; 4,306,157; 5,440,176; 6,647,716; 6,806,586; 6,982,498; 6,995,479; and 7,011,501. The applications are contained in United States patent publication nos. 2002/0034437; 2002/0158472; 2003/0201645; 2005/0285404; and 2005/0285405.
Finally, there are four patents and one patent application dealing with a hydroelectric turbine blade having no central shaft. These are U.S. Pat. Nos. 5,592,816; RE38,336; 6,648,589; and 6,729,840. The patent application is U.S. patent application Ser. No. 10/633,865, which has been published as United States patent application publication no. 2005/0031442. In the Hydroelectric Turbine of the patent application, magnets are used as bearings to maintain the alignment of the rotor blade. To generate electricity this Hydroelectric Turbine has “ . . . magnets imbedded in the periphery of its blade and cores imbedded in its housing.” Thus, the blade serves as a rotor of an electrical generator; and the housing functions as the stator of such a generator. Consequently, though, the outer diameter of the blade must be less than the inner diameter of the stator.
Additionally, two patents, although not dealing with the production of electricity from ocean currents, do disclose underwater tracked systems. U.S. Pat. No. 3,943,644 describes a dredge which utilizes “a flexible combined guide train and conveying train assembly” to move buckets containing scraped sediments to a boat. And U.S. Pat. No. 4,422,799 discloses the use of a marine railway system to install submarine pipelines.
None of the preceding patents or applications, however, employ trolleys that are propelled by blades along a track to which the trolleys are mounted either through wheels or by magnetic levitation.
With regard simply to the general concept of magnetic levitation there are also a number of United States patents and patent publications.
The patents include U.S. Pat. Nos. 5,511,488; 5,953,996; 6,357,359; 6,633,217; 6,664,880; and 6,899,036.
Exemplary patent publications are United States patent publication nos. 2003/0005851; 2003/0112105; 2003/0217668; 2004/0119358; 2004/0123766; 2005/0204948; and 2006/0016365.
Furthermore, a team at Lawrence Livermore National Laboratory headed by physicist Richard Post has disclosed an Inductrack concept, which is a technology for magnetic levitation.
“Inductrack involves two main components: a special array of permanent, room-temperature magnets mounted on the vehicle and a track embedded with close-packed coils of insulated copper wire. The permanent magnets are arranged in configurations called Halbach arrays, named after Klaus Halbach, retired Lawrence Berkeley National Laboratory physicist . . . . ”
The inventors did not locate a patent for the original Inductrack, itself; but the following United States patents appear to be variations of the basic concept: U.S. Pat. Nos. 6,629,503; 6,758,146; 6,827,022; and 6,983,701.
Still, the inventors are unaware of any patent or product which utilizes magnetic induction in a device to produce electricity from fluid currents.
Magnetic bearings are the subject of the following exemplary patents: U.S. Pat. Nos. 5,177,387; 5,710,469; and 5,747,426.
Again, however, the use of magnetic bearings in a device to produce electricity from fluid currents is unknown to the inventors.